Simple gas chromatography analysis of faecal butyrate: application to patients at risk of pouchitis.

In spite of the fact that pouchitis is the most frequently occurring and troublesome complication found in patients treated by ileo-anal anastomosis for ulcerative colitis, no biological marker currently exists to monitor the outcome of the disease. Since it has been noted faecal butyrate is reduced in patients with pouchitis, we developed a simple gas chromatography method to quantify butyrate in faecal water. This test is based on diethyl ether extraction with the use of methacrylic acid as an internal standard. We demonstrated that butyrate was effectively measured when this technique was applied to eleven patients with ileal-pouch anal anastomosis within the first year after the closure of their ileostomy. We also observed a noticeable reduction in the concentration of butyrate in patients who went on to develop a pouchitis.

Pouchitis is associated with mucosal imbalance between interleukin-8 and interleukin-10.

BACKGROUND: Mucosal lesions of pouchitis are characterized by a neutrophil infiltrate. Interleukin (IL)-8 is the main mediator involved in neutrophil recruitment and is down-regulated by IL-10. AIM: To look for an imbalance between IL-8 and IL-10 in patients with pouchitis. PATIENTS/METHODS: 18 patients having an ileoanal pouch for ulcerative colitis were studied. Eleven had pouchitis defined by the pouchitis disease activity index of > or =7 points and 7 had no history of pouchitis. Biopsies taken at the site of inflammation or in the normal mucosa were scored for the histologic lesions, the intensity of neutrophil infiltration, and the presence of crypt abscesses. Mucosal IL-8 and IL-10 mRNA were quantified by competitive polymerase chain reaction. RESULTS: IL-8, IL-10, and IL-10/IL-8 mRNA were similar in patients with or without pouchitis. IL-8 mRNA levels were significantly higher in patients with a histologic score >2 (p = 0.01) and in patients with crypt abscesses (p = 0.01). IL-10/IL-8 mRNA was significantly lower in patients having a histologic score >2 (p = 0.019), a neutrophil infiltration > or =10% (p = 0.013), and crypt abscesses (p = 0.01). CONCLUSION: Histologic lesions of pouchitis are associated with a mucosal imbalance between IL-8 and IL-10. IL-10 could be proposed as a new treatment for pouchitis.

Inflammatory alterations in mesenteric adipose tissue in Crohn's disease.

BACKGROUND & AIMS: Abnormalities of fat in the mesentery including adipose tissue hypertrophy and fat wrapping have been long recognized on surgical specimens as characteristic features of Crohn's disease. However, the importance, origin, and significance of the mesenteric fat hypertrophy in this chronic inflammatory disease are unknown. Peroxisome proliferator-activated receptor gamma (PPARgamma) is a crucial factor involved in the homeostasis of adipose tissue, a major source of biologically active mediators. METHODS: Intra-abdominal fat accumulation was quantified using a magnetic resonance imaging method in patients with Crohn's disease and controls. PPARgamma and inflammatory cytokines synthesized by mesenteric adipose tissues were assessed by quantitative polymerase chain reaction, in situ hybridization, and immunohistochemistry. RESULTS: In vivo, patients with Crohn's disease have an important accumulation of intra-abdominal fat. This mesenteric obesity, present from the onset of the disease, is associated with overexpression of PPARgamma and tumor necrosis factor (TNF)-alpha, synthesized, at least in part, by adipocytes. CONCLUSIONS: These results suggest that confined increased PPARgamma mesenteric concentrations could lead to the mesenteric fat hypertrophy, which could actively participate through the synthesis of TNF-alpha in the inflammatory response.